Why is this Toyota stalling?

What is your question?

We purchased this car used from a neighbor. He indicated there was a problem, but they assumed it was the Throttle Position Sensor, which he indicated was an inexpensive part to replace. Since then, this car has been towed home on at least 4 occasions, it has stalled out at intersections--the RPMS just drop off and it stops idling. We have replaced fuel pump, fuel filter, coil, distributor, plugs, wires, crank position sensor--and it still stalls. The auto mechanic hooked the car to the computer and it and nothing appears to be malfunctioning. Then we get it home and it stalls again. This car is like a money pit--we thought it would be reliable for our daughter and it spends more time at the repair shop than on the road! I don't even want to insure it anymore because we rarely get to drive it. Last month it was at the shop for 6 weeks.